Wheel suspension for crab supporting wheels of an overhead travelling crane



Jan. 31, 1967 F. DE GASPERIS 3,301,409

WHEEL SUSPENSION FOR GRAB SUPPORTING WHEELS OF AN OVERHEAD TRAVELLINGCRANE Filed May 17, 1965 3 Sheets-Sheet l 8 27 IX\ i...

F. WHEEL SUSPENSION FOR CRAB SUPPORTING WHEELS Jan. 31, 1967 DE GASPERISOF AN OVERHEAD TRAVELLING CRANE 3 Sheets-Sheet 2 Filed May 17, 1965 1967F. DE GASPERIS 3,301,409

WHEEL SUSPENSION FOR CRAB SUPPORTING WHEELS OF AN OVERHEAD TRAVELLINGCRANE Filed May 17, 1965 3 Sheets-Sheet s United States Patent 3,301,409WHEEL SUSPENSION FOR CRAB SUPPORTING WHEELS OF AN OVERHEAD TRAVELLINGCRANE Franco De Gasperis, Turin, Italy, assignor to Societa Nazionaledelle Oificine de Savigliano, Turin, Italy Filed May 17, 1965, Set. No.456,450 Claims priority, application Italy, June 16, 1964, 13,417/ 64 2Claims. (Cl. 212-18) This invention relates to travelling cranes of thetype comprising a main girder of box section and two side girderstransversely secured to the ends of such main girder and equipped withsupporting wheels adapted to run on tracks, said main girder serving tosupport a crab which is movable longitudinally thereof and carries loadhoisting equipment.

In single girder cranes the lifting cables must necessarily be supportedfrom the crab overhanging one side wall of the girder, therefore, thecrab when under load is subjected to a tilting force.

It is the chief object of the invention to provide a crane of the typementioned above, which is simple and sturdy in construction and whereinthe crab is conveniently guided and linked to the main girder so as tooppose the tilting force acting on it when in loaded condition.

A further object of this invention is to provide a crane of the abovementioned type, wherein the stresses to which the loaded crab issubjected are distributed over reinforced areas of the girder.

With the above and further objects in view, this invention provides atravelling crane of the type specified, wherein the main girder isprovided with a first rail extending along the top edge of that sidewall of the girder nearest the load suspension means and with a secondrail which is carried by a supporting structure at the other side wallof said girder in such a manner as to be disposed in spaced parallelrelation to the top wall of the girder, said second mentioned railcomprising a fiat structural member having dual tracks one facingupwardly and the other downwardly while the travelling crab is equippedwith at least two supporting wheels engaging said first rail and with atleast two wheels adapted to engage the bottomsurfaces of said secondrail at opposite sides of the rail supporting structure, and at leasttwo wheelsadapted to roll over the top surface of said second rail.

In order that the invention may be clearly understood and readilycarried into effect reference will now be made to the accompanyingdrawings in which:

FIGURE 1 is an elevational view of a single girder crane on which a hookcarrying crab is supported,

FIGURE 2 is a top plan view of the girder section carrying thetravelling crab,

FIGURE 3 is an elevational view taken in the .direction of the arrow IIin FIGURE 2,

FIGURE 4 is a side elevation looking in the direction of the arrow IIIin FIGURE 2,

FIGURE 5 is a detail of a suspension member,

FIGURE 6 is a perspective view showing a portion of the crab body,

FIGURE 7 is a perspective view of the suspension member shown in FIGURE5,

FIGURE 8 is a plan view of a detail of the wheel suspension of FIGURE 2,and

FIGURE 9 is a sectional view along line IX-IX of FIGURE 8.

The crane comprises a main girder 1 of box shape having secured theretoat each end side girders 2, which are equipped with wheels 2a for thetravel of the crane over the parallel tracks 3.

In the embodiment shown in the drawings the girder 1 comprises twovertically extending side walls 1a, 1b and two horizontally extendingmembers 10, 1d forming the top and bottom walls of the girder. Aplurality of transverse partitions 1e are spaced equidist-antly alongthe interior of the girder for reinforcement thereof.

A crab 4 is mounted for longitudinal movement over the girder andcomprises a flat platform of known type, adapted to support the loadhoisting members comprising an electric motor 14 and a differentialwinding drum 13 lifting a hoisting hook 12 which overhangs the side wall111 of the girder. The crab is provided with known power means forlongitudinal movement over the girder 1.

The crab 4 is provided on the side nearest the hoisting hook, with atleast two supporting wheels 5 adapted to roll over a rail 6 secured tothe top edge of the side wall 1a.

A supporting structure is secured to the opposite side wall 112 of thegirder and in the embodiment illustrated comprises a plurality ofstandards 17 which may be in the form of struts, equi-distantly spacedalong the length of the girder. The struts 17 are arranged substantiallyparallel with the side Wall 1b and extend vertically beyond the top wall10.

A rail 18 is secured to the top of the struts 17 such rail comprising afiat structural member having an upper and a lower track face.

The rail 18 is of such width as to extend beyond both sides of thestruts 17, and runs parallel to the girder above the plane of the topwall 10.

The struts 17 are secured to the girder side wall 1b at pointscoinciding with the location of the stiffening partitions 12 in order toreinforce said wall against stresses acting on the rail 18.

According to this invention the crab 4 is provided with a laterallyextending 'arm 4a at that side remote from the load suspension means.The top of the arm 4a carries a block 20 which is capable of limitedsliding movement inwardly and outwardly as indicated by the arrows inFIGURE 6 and is provided at opposite sides with projecting pins 21.These pins which are axially aligned extend substantially parallel withthe rail 18.

A pendant support 22 is suspended from the pins 21 and comprises a pairof inverted U shaped members 23 which are spaced apart andinterconnected by side members 24.

The top forming the base of each inverted U shaped member 23 iselongated into an angular apex 23a (FIG- URE 7) the arrangement beingsuch that the support 22 will swing freely on the pins 21.

Two shafts 7a are attached to and extend inwardly from the side members24 of the support 22 and carry wheels 7 which 'are adapted to engage thebottom surface of the rail 18.

The spacing between the members 23 of the support 22 is such as to allowthe arm 4a to extend t-herethrou-gh upon transverse sliding of the block20.

With the above described construction the tilting force acting on thecrab under load is borne by the rail 18, being distributed over thelength thereof and taken up by the struts 17 affixed to the girder.

Attached to the laterally extending arm 4a of the crab is a carriageserving to support a pair of wheels 8 which ride over the rail 18, saidcarriage consisting of a frame member 25 which is attached at itsmidpoint to the end of said arm 4a. The member 25 extends parallel toand above the rail 18 and has at each end an inwardly directed stud 26.Pivotally mounted on each stud 26 is a forked support 27 which as can beseen from FIGURES 8 and 9 is adapted to support a wheel 8 and isprovided at that end remote from the stud 26 within a circular portion28 so formed as to provide a dished recess which accommodates one end ofa coil spring 29. The upper end O of the spring 29 engages a groovedretaining disc 30 which is held against the spring 29 by :a bolt 32threaded into a cup-shaped retainer 31 which latter together with thedished recess of the portion 28 forms a cylindrical housing for thespring 29.

The head of the bolt 32 engages the lower face of a plate 33 which isattached to the member 25. In this manner a resilient suspension isprovided for the wheels 8 which can be varied as to its loading by thetensioning of the spring 29. This is effected by the adjustment of the'bolt 32 as to its relative position in compressing the spring 29.

The above described suspension system is the same at both ends of theframe member 25 so that both wheels 8 ride over the rail 18 in abalanced, spring suspended carriage.

The fact that ample provision is made for any lateral deviation whichmay be encountered in the travel of the crab by virtue of the presenceof the pivoted support 22 carried by the slidable block 20, results notonly in a smooth operation but also in compensation for any unevennessof the rails.

The number of wheels for the suspension of the crab, both for the upperand the lower rail faces, may of course, be increased depending upon theload requirements of the crane assembly.

A protecting hand-rail 4c is provided as indicated in FIGURE 3 as asafety measure for those who are charged with the maintenance of theequipment. A platform 1 is also attached to the girder 1 at the sidewall 1b serving as a gangway for those who have to have access inservicing the equipment.

What I claim is:

1. Wheel suspension for crab supporting Wheels of an overhead travellingcrane comprising a box girder, a crab having a body mounted on saidgirder for movement therealong, a first r-ail attached to said girderextending along the top of said girder at one side thereof and havingits running surface facing upwardly, load suspension means carried bysaid crab disposed laterally outwards of said rail at said one side andtending to tilt said crab in one direction about said rail, a secondrail attached to and extending along the other side of said girder andhaving tworunning surfaces, one running surface facing the oppositedirection to said one direction, the other running surface facing saidone direction and wheels mounted on said crab and arranged to run on therunning surfaces of said rail, wherein the Wheels arranged to run onsaid one running surface of the second rail are attached to a dependingsupport swingably supported from pins extending parallel to said secondrail, said pins being affixed to a block slideably mounted on the crabbody in a direction transverse to said second rail.

2. Wheel suspension as claimed in claim 1, wherein the wheels arrangedto run on said other running surface of the second rail are each mountedin a forked support extending above the second rail and pivotallymounted on pivots fixed to the crab body transversely of the secondrail, a compression spring urging said forked support towards the secondrail being provided between said forked support and the crab body.

References Cited by the Examiner UNITED STATES PATENTS 3,040,675 6/1962Rudolfi 104118 3,194,179 7/1965 Scherer 21217 X FOREIGN PATENTS1,344,767 10/ 1963 France. 1,375,775 9/1964 France.

ANDRES H. NIELSEN, Primary Examiner.

EVON C. BLUNK, Examiner.

A. L. LEVINE, Assistant Examiner,

1. WHEEL SUSPENSION FOR CRAB SUPPORTING WHEELS OF AN OVERHEAD TRAVELLINGCRANE COMPRISING A BOX GIRDER, A CRAB HAVING A BODY MOUNTED ON SAIDGIRDER FOR MOVEMENT THEREALONG, A FIRST RAIL ATTACHED TO SAID GIRDEREXTENDING ALONG THE TOP OF SAID GIRDER AT ONE SIDE THEREOF AND HAVINGITS RUNNING SURFACE FACING UPWARDLY, LOAD SUSPENSION MEANS CARRIED BYSAID CRAB DISPOSED LATERALLY OUTWARDS OF SAID RAIL AT SAID ONE SIDE ANDTENDING TO TILT SAID CRAB IN ONE DIRECTION ABOUT SAID RAIL, A SECONDRAIL ATTACHED TO AND EXTENDING ALONG THE OTHER SIDE OF SAID GIRDER ANDHAVING TWO RUNNING SURFACES, ONE RUNNING SURFACE FACING THE OPPOSITEDIRECTION TO SAID ONE DIRECTION, THE OTHER RUNNING SURFACE FACING SAIDONE DIRECTION AND WHEELS MOUNTED ON SAID CRAB AND ARRANGED TO RUN ON THERUNNING SURFACES OF SAID RAIL, WHEREIN THE WHEELS ARRANGED TO RUN ONSAID ONE RUNNING SURFACE OF THE SECOND RAIL ARE ATTACHED TO A DEPENDINGSUPPORT SWINGABLY SUPPORTED FROM PINS EXTENDING PARALLEL TO SAID SECONDRAIL, SAID PINS BEING AFFIXED TO A BLOCK SLIDEABLY MOUNTED ON THE CRABBODY IN A DIRECTION TRANSVERSE TO SAID SECOND RAIL.